Clean cutover — Kotlin off NewPipeExtractor, onto uniffi.strawcore

Brings the Phase U Android-side integration onto a feature branch
where the rust wrapper now bridges to strawcore-core (the new NPE
port) instead of rustypipe.

  * strawApp/build.gradle.kts — JNA dep + cargoBuild + cargoBuildHost
    + uniffiBindgen + the merge/compile task wiring. libs.newpipe
    .extractor dropped.
  * StrawApp.kt — uniffi.strawcore.initLogging(); NewPipe.init() gone
  * 5 ViewModels (Search/VideoDetail/Player/Channel/Subscriptions)
    swapped to call uniffi.strawcore.{search,streamInfo,channelInfo}
  * PlayerScreen + PlaybackService adjusted for the new StreamInfo
    shape (dash_mpd_url / hls_url instead of NPE's manifests)
  * IosSafeHttpDataSource carried forward — strawcore-core gives us
    Android-primary URLs so the iOS cap path is mostly dead code,
    but kept as belt-and-suspenders for the rare HLS-fallback
  * NewPipeDownloader.kt + util/Thumbnails.kt deleted

Files taken wholesale from sulkta branch — the wrapper's UniFFI
surface is identical between sulkta (rustypipe-backed) and the
current Phase-7-bridged-to-strawcore-core code, so Kotlin doesn't
care which extractor is under the hood.

strawApp/build.gradle.kts

@@ -95,7 +95,9 @@ dependencies {
     implementation(libs.coil.network.okhttp)
 
     // NewPipeExtractor (JVM/Android-only) + its OkHttp dep
-    implementation(libs.newpipe.extractor)
+    // libs.newpipe.extractor — REMOVED in Path C-6. Extractor is now strawcore
+    // (Rust + rustypipe via UniFFI). See rust/strawcore/ + the cargoBuild +
+    // uniffiBindgen Gradle tasks below.
     implementation(libs.squareup.okhttp)
 
     // JSON for SponsorBlock + Return YouTube Dislike clients
@@ -110,4 +112,95 @@ dependencies {
     implementation("androidx.media3:media3-session:1.4.1")
     // Guava ListenableFuture support for awaiting MediaController connect.
     implementation("androidx.concurrent:concurrent-futures-ktx:1.2.0")
+
+    // strawcore — Rust YouTube extractor via UniFFI/JNA. Built by the
+    // cargoBuild + uniffiBindgen tasks below; phase U-2+ exposes search /
+    // streamInfo / channelInfo to replace NewPipeExtractor.
+    implementation("net.java.dev.jna:jna:5.14.0@aar")
 }
+
+// =============================================================================
+// Phase U-1 / Path-C-2 — Rust core build glue.
+//
+// Two tasks chain into the Android build:
+//   cargoBuild       — cross-compiles rust/strawcore for the four Android ABIs
+//                      via cargo-ndk and drops the .so files in strawApp/src/main/jniLibs/.
+//   uniffiBindgen    — generates the Kotlin bindings from the freshly-built lib
+//                      into strawApp/src/main/java/uniffi/strawcore/.
+//
+// Both depend on:
+//   - cargo + rustup with the four Android targets installed
+//   - cargo-ndk on PATH
+//   - ANDROID_NDK_HOME pointing at an NDK with the right toolchains
+// All of that lives in the build-host container.
+// =============================================================================
+
+val rustRoot = file("../rust").absolutePath
+val jniLibsDir = file("src/main/jniLibs").absolutePath
+val bindingsDir = file("src/main/java").absolutePath
+
+val cargoHome: String = System.getenv("CARGO_HOME") ?: "/caches/cargo"
+val cargoBin: String = "$cargoHome/bin/cargo"
+val ndkHome: String = System.getenv("ANDROID_NDK_HOME")
+    ?: System.getenv("ANDROID_NDK_ROOT")
+    ?: "/caches/android-sdk/ndk/27.2.12479018"
+// Honor CARGO_TARGET_DIR if set (we redirect it to /caches on build-host
+// because the container's writable rootfs hits 100% before the cross-compile
+// for 4 ABIs finishes). Falls back to the default `<workspace>/target`.
+val cargoTargetDir: String = System.getenv("CARGO_TARGET_DIR")
+    ?: "$rustRoot/target"
+
+val cargoBuild by tasks.registering(Exec::class) {
+    group = "rust"
+    description = "Cross-compile strawcore for all Android ABIs via cargo-ndk."
+    workingDir = file(rustRoot)
+    environment("ANDROID_NDK_HOME", ndkHome)
+    environment("PATH", "$cargoHome/bin:${System.getenv("PATH") ?: ""}")
+    commandLine = listOf(
+        cargoBin, "ndk",
+        "-t", "arm64-v8a",
+        "-t", "armeabi-v7a",
+        "-t", "x86",
+        "-t", "x86_64",
+        "-o", jniLibsDir,
+        "build", "--release", "-p", "strawcore",
+    )
+    standardOutput = System.out
+    errorOutput = System.err
+}
+
+val cargoBuildHost by tasks.registering(Exec::class) {
+    group = "rust"
+    description = "Build host-arch debug strawcore so bindgen can read its UniFFI metadata."
+    workingDir = file(rustRoot)
+    environment("PATH", "$cargoHome/bin:${System.getenv("PATH") ?: ""}")
+    commandLine = listOf(cargoBin, "build", "-p", "strawcore")
+    standardOutput = System.out
+    errorOutput = System.err
+}
+
+val uniffiBindgen by tasks.registering(Exec::class) {
+    group = "rust"
+    description = "Generate Kotlin bindings for strawcore via uniffi-bindgen."
+    dependsOn(cargoBuildHost)
+    workingDir = file(rustRoot)
+    environment("PATH", "$cargoHome/bin:${System.getenv("PATH") ?: ""}")
+    commandLine = listOf(
+        cargoBin, "run", "--quiet", "--bin", "uniffi-bindgen", "--",
+        "generate",
+        "--library", "$cargoTargetDir/debug/libstrawcore.so",
+        "--crate", "strawcore",
+        "--language", "kotlin",
+        "--no-format",
+        "--out-dir", bindingsDir,
+    )
+    standardOutput = System.out
+    errorOutput = System.err
+}
+
+// Make sure Android's JNI-libs merge picks up the freshly built .so files,
+// and Kotlin compilation can resolve the generated bindings.
+tasks.matching { it.name.startsWith("merge") && it.name.endsWith("JniLibFolders") }
+    .configureEach { dependsOn(cargoBuild) }
+tasks.matching { it.name.startsWith("compile") && it.name.endsWith("Kotlin") }
+    .configureEach { dependsOn(uniffiBindgen) }